From www.signonsandiego.com (article about growth hormone)

"A few years back, several sprinters from the same track club arrived at an early-season meet – all wearing braces.

There are two likely explanations. Either they decided the sudden need to straighten their teeth and got a group discount at a local orthodontist, or they were taking growth hormone and had no choice.

Unlike steroids, which target muscles, growth hormone makes a lot of things bigger – muscles, bones, internal organs, hands, feet, foreheads, jaws. In some cases, your lower jaw elongates and your teeth splay. It can be an annoying side effect, but for many athletes it's a small price of (and for) fame. What are a few months of picking food out of your braces in the name of a sub-10-second 100 meters? "

Very true actually...to name a few: Marion Jones and Torri Edwards...might their braces be connected to this problem? As far as I know both of them have been accused of doping...